For this reason, 0. When external capacitors are used with any IC regulator, it is some- times necessary to add protection diodes to prevent the capacitors from discharging through low current points into the regulator. This list is only representative. Considerable effort was expended to make the LMXX series of regulators easy to use and minimize the number of external components.

Since does not switch OFF under short- circuit load, it must be a power device with heat sink adequate to handle the short circuit dissipation. The adjustment terminal can be bypassed to ground on the LM to improve ripple rejection.

LMH semiconductor

If the regulator output is grounded the pass device may fail and short, destroying the regulator. Constructed on a single monolithic chip is a temperature stabilizer circuit and an active reference zener. The data above represent pulse test conditions with junction temperatures as indicated at the initiation of tests. Some ml305h transistors are listed below.

It is desirable to eliminate the weight and cost of chokes. Positive feedback for hysteresis is applied to the LM through R6.

Actually, all the voltages calculated are assumed to be full load. Capacitor C1 is optional to improve ripple rejection so that 80 dB is obtained at any output voltage. These, however, are often larger in capacity and price than is necessary for one-per-card use.

When an output capacitor is connected to a regulator and the input is shorted, the output capacitor will discharge into the output of the regulator. Further, the LM series features internal current limiting, thermal shutdown and safe-area compensation, making them virtually blowout-proof against overloads.

The LMLA is an improved version of the Datassheet series with a tighter output voltage tolerance specified ,m305h the full military temperature rangehigher ripple rejection, better regulation and lower quiescent current. The variable regulators are most useful for providing non-standard voltages, switching regulators, or in programmable-voltage high current supplies with lm305u current-limiting.

The current set resistor connected between the adjustment terminal and the out- put terminal usually fi should be tied directly to the output of the regulator rather than near the load. Transient re- sponse of all the regulators is improved when output capacitors are added. Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Ceramic capacitors are also good at high frequencies, but some types have a large decrease in capacitance at frequencies around 0.

Thermal regulation depends on IC layout as well as electrical design. The transformer may be constructed with materials capable of withstanding higher tempera- tures and be a perfectly valid design.

Further, both line and load regulation are better than standard fixed regulators. An adjustable regulator is mandatory since, for long battery life the float voltage must be precisely controlled. Both current regulators need a negative supply to operate down to ground. The LM is an IC zener with less than m dynamic impedance and can operate over a range of 0.

One of the more esoteric problems encountered by the circuit designer is the selection of power transformer ratings for a particular DC power supply. Usually the 5 mA programming current is sufficient; however, worst case minimum load for commercial grade parts requires a minimum load of 10 mA.

The regula- tor will shutdown at any desired level above 3 V BEwithout overheating transistor Q4. The low dynamic impedance simplifies biasing and the wide operating current allows the replacement of many zener types. Values given may be increased without limit. The output current causes an l-R drop across R1 which brings transistor Q1 into conduction. Curren t NSC Equiv.